(A) All lots shall be cleared entirely of combustible material. If the Chief or his agent declares this to be impractical, the guidelines set up in Section 11.504 shall be used.
(B) Any person owning, leasing, controlling, operating or maintaining any building or structure in, upon, or adjoining any hazardous fire area, and any person owning, leasing or controlling any land adjacent to such buildings or structures, shall at all times maintain around and adjacent to such building or structure an effective fire-break made by removing and clearing away, all combustible material for a distance not less than 100 feet from all portions of the structure. This section shall not apply to single specimens of trees, ornamental shrubbery or similar plants used as ground covers, provided that they do not form a means of rapidly transmitting fire from the native growth to any structure.
('81 Code § 15.18.040)